Motion-transmitting mechanism



Feb. 17, 1942. B. BRASSELL 2,273,173

MOTION-TRANSMITTING MECHANISM Filed March 11, 1941 3 Sheets-Sheet 1mill-51a 420 I 3 flryan firassali Feb. 17, 1942. B. BRASSELLMOTION-TRANSMITTING MECHANISM Filed March 11, 1941 3 Sheets-Sheet 2 oolFeb. 17, 1942. B. BRASSELL 2,273,113

MOTION- TRANSMITTING MECHANISM Filed March 11, 1941 3 Sheets-Sheet 3 I MF 8 aw I 3 ,9, m s as i W 16 a v fi I I I v II l Hill] m M 17 Z 0 If H nm/ Patented Feb. 17, 1942 UNITED STATES PATENT OFFICE 18 Claims.

This invention relates to improvements in motion-transmitting mechanism,and relates more particularly to mechanism involving the driving of areciprocating driven member and more specifically where such drivenmember is being driven by a reciprocating drive member.

In mechanical motion which includes a reciprocating drive member, one ofthe problems is that presented through the condition which is presentWithin the end zones of the reciprocating stroke. At such time themember is moving in one direction, must come to a stop, and then beginits stroke in the opposite direction; the two strokes are thus separatedby an instant in which the inertia of motion of the first stroke must beovercome and brought to its end to form a momentary inertia of rest, andthen a new inertia of motion characteristic exerted in the oppositedirection, must be developed. At very slow speeds the conditions areless difiicult, but as the speed increases, the difiiculties are largelyaccentuated through the fact that the speed of approach is greater butmust come to its end at the same instant at all speeds of approach; and,after coming to the stop, the stroke in the opposite direction mustrapidly develop the running speed, by overcoming the inertia of rest anddeveloping the inertia of motion exerted in the opposite direction. Thesudden transitions required will tend to set up conditions of a hammerblow or knock, and thus affect the smooth running of the mechanism.

A favorite method of meeting the conditions is by arranging themechanism so that the reciprocating member is driven by or drives amember rotating in a circular path--as, for instance, the crank of acrank shaft, as illustrated, for instance, in the steam engine or theinternal combustion engine, where the piston is connected with the crankby a crank, one end of which reciprocates and the other is movablethrough a circular path; the latter end limits the stroke of the piston,and at the same time serves to gradually decrease the speed of approachof the piston to the end of its stroke through the movement of the crankshaft through the zone of its dead center position. A similar effect isset up if the reciprocating member is being driven from a crank-shaft,the circular travel of the latter setting up the speed decrease throughthe passage of the crank through the dead center zone.

The conditions are complicated in certain types of mechanism, such, forinstance, as deep well operations-operations where the driven member isof considerable or great length, although the stroke of reciprocationmay itself be comparatively short. For instance, a deep well has itsstorage basin at considerable depth, requiring the pumping piston to beat the end of a lengthy connection with the power drive member; not onlyis the Weight of the connection a factor, but, in addition, the weightof the liquid being pumped and located above the piston provides anadditional weight factor during the upward movement of the piston. Inthe downward travel in Which the piston cup is open, the weight of theconnection adds its effects to increase the value of the inertia ofmotion, and thus-aids in producing the hammer-blow effect; on theopposite stroke, the weight of the connection and of the trapped liquidopposes the overcoming of the inertia of rest, and thus tends to put astrain on the structure at such instant. Here, also, the factor of speedadds to the character of the problems since speed of approach increasewill tend to increase the hammer-blow effect, and, at the same time,will increase the strain effect at the instant of change, since thepiston must pass more rapidly from its position of repose to that of therunning speed.

As a result, operations in this particular field are subject to certainconditions which must be met if the activities are to be under smoothrunning conditions. For instance, if the power be that of a wind-wheelstructure, in which the primary motion is circular, the mechanism isarranged to limit the speed so as to provide a sufficient time factorwithin the dead-center zone such that the speed of approach, stop, andstroke start in the opposite direction can take place without serioushammer-blow or strain efiects. The same is true where a driven pump jackis the prime mover, the oscillations of the latter being the source forthe driven member reciprocation. Various forms of mechanism have beenemployed with a view to increasing the output--as by amplifying thestroke of the piston, etc., but in such cases there has generally beenadded a shock-absorber device (springs or weights, etc.) since it isinevitable that the increased speed developed also increases thehammer-blow and strain effect referred to, the shockabsorber structurebeing designed to reduce the effect of these as far as possible.

The present invention is designed to meet the general problem in asomewhat different wayby placing the solution of the problem directlywithof the power source an additional action which tends to reduce thehammer-blow effect and the strain of overcoming the inertia of rest,doing this by dividing the pump rod structure into drive and drivenelements operatively connected through a unit which itself communicatesthe drive to the driven member but permits variation in the speed ofapproach and the power effect in overcoming inertia in such way as todecrease the speed of approach and to decrease the initial speed at theinstant of overcoming the inertia of rest, this action being additionalto that which may be provided by the dead center zone action referred toabove. Since it is apparent that after the inertia of rest has beenovercome, the inertia of motion can be accelerated by the use ofsufficient power, it becomes apparent that the speed of travel of thepump rod can be increased between the end zones of reciprocation, sothat any tendency of delay within the end zones of reciprocation willnot lower the speed of operation and pumping effeet-the tendency will beto increase itand at the same time the likelihood of damage to equipmentthrough the hammer-blow and strain effect will be largely decreased. Inother words, the normal power speed may be increased without danger,since the possible damaging effects within the end zone of reciprocationhave been decreased to an extent such that a considerable speed increasecan be provided without bringing these effects beyond the limitsheretofore deemed permissible. Hence, the average speed of the assemblyis increased over that of the structures heretofore used for thepurpose.

The assembly has the additional advantage of having the reciprocatingmember, which provides the drive member of the assembly, comparativelyshort and therefore capable of being accurately guided in its linearmovements, while the driven member-the pump rod-requires no specialguiding structure so that the length of the latter offers nocomplications with respect to the guiding of its reciprocations, theupper end of the pump rod being operatively connected to the drivemember through the unit, while the lower end of the pump rod has theusual piston assemblage structure usually present in such welloperations.

The unit comprises a leverage system which, r

in cooperation with controlling guiding faces, has the effect of causinga relative movement between the drive and driven members within the endzone, doing this without disturbing any of the connections, the relativemovement decreasing the throw of the driven member as the drive memberapproaches the end of its stroke, and then building up the normal directdrive speed relationship between the members during travel of the drivemember from its rest position for a distance equal to that during whichthe previous stroke-decreasing action took place, with the restorationmovement also caused by such cooperation of the leverage system and thecontrolling face. In other words, the travel of the drive member remainsnormal throughout the cycle, but the travel of the driven member, whichis uniform with the drive member excepting in such end-zones, becomesvaried from the drive member within such end zones, with the variationactive to reduce the length of travel of the driven member during theapproach to the stroke end of the drive member travel, and then torestore the normal condition during a corresponding length of travel ofthe drive member at the beginning of the return stroke.

This difference in action within the end zone is not dependent on therate of advance of the drive member within the zone, but is the resultof such advance. Hence, the action is superimposed upon any action inthe direction of decrease in speed of advance of the drive member thatwould be provided by the action of a power crank within the dead centerzone. In other words, while movement of the drive member in such endzone to its dead center position shortens the travel distance of suchmember without affecting the timean action which would be applied to thedriven member through the direct connection, the action of the unit,within the same time, is to decrease additionally the length of travelof the driven member, so that the ultimate result is to cause the lengthof travel of the driven member to be less than that of the drive memberwithin such dead-center zone, with the result that the driven member isbrought to its dead center position at a rate slower than that of thedrive member in reaching its dead center point, regardless of the timein which such travel takes place, the gradual decrease in rate ofadvance due to the deadcenter zone effect being carried directly intothe action of the driven member.

Hence, at the instant of change in direction of reciprocation, theconditions are most favorable for overcoming the resistance of the load,since the start of the return stroke is under the conditions set up bythe previous approach stroke. At such instant the conditions of leverageare made more favorable for overcoming the inertia of rest, and afterthe load begins to move and to set up the condition of inertia ofmotion, the unit acts to restore the normal by the travel of the drivenmember through such decreased distance during travel of the drive memberduring the remainder of the dead-center zone, so that, as the normalrelationship between the members is restored, the drive and drivenmembers will again inove as a unit through the direct drive condiion.

One of the characteristics of the present invention lies in the factthat although the drive member is active at all times as the powersource, and the unit at all times acts to operatively connect the driveand driven members, the primary control of the driven member movementspasses from the drive member to the unit when the members are in suchend zones of reciprocation, returning to the drive member when out ofsuch zone. Because of this the length of such zone is predetermined andis provided by the particular arrangement of the control faces of theunit, the latter determining the value of the variations from the normalset by the drive member reciprocations. In other words, it is possibleto control the rate and value of the variations by the particular formof the control faces-after the rate and value have been fixed, theyremain constant in action. Hence, in designing the unit, the operatingconditions can be considered, and the pattern of the control facesarranged to provide the best efficiency in this respect, the unit thenoperating under the designed conditions.

While the presence of the seeming yield by the driven member duringapproach within the end zone of reciprocation may appear to present ananalogy to structures of the shock-absorbing type, employing springs,weights, or the like, the unit action is of a different type. Wheresprings,

etc., are employed to permit the yield, the necessity for direct actionoutside of the end zones requires that no yield be present exceptingwithin the end zones; hence, the springs must be of suffrcient effectiveresistance as to avoid yield excepting when the end zone is reached,assuming the springs are active at all times; in such case, the springsmust be brought into action by some mechanism, and when brought intoaction serve to increase the resistance to the movement of the drivenmember, during approach, and acting as an auxiliary power source at thebeginning of the return stroke. If the springs are actual cushions andotherwise separate from the mechanism, serving as a true shock absorber,the same conditions are present, but leave the direct connection as ofthe type or characteristic of a lost motion device with possibility ofderangement. In the present invention, these conditions are avoided, theoperative connections remaining constant throughout the cycle-the yieldis set up by the leverage system itself acting with the control faces,so that the yield is actually a part of the normal operation of theassembly.

To these and other ends, therefore, the nature of which will be madeapparent as the invention is particularly described, said inventionconsists in the improved construction and combinations of partshereinafter more particularly described, illustrated'in the accompanyingdrawings, and more particularly pointed out in the appended claims.

In the accompanying drawings, in which similar reference charactersindicate similar parts in each of the views Figure l is a diagrammaticview illustrating the basic features of the invention, including theseof the unit, the parts being shown in a position where the drive anddriven shafts are operating under the conditions of a one-to-one driverelationship.

Figure 2 is a fragmentary diagrammatic View of a portion of Figure 1,the position shown presenting the elements as beginning the actionwithin the end-zone of reciprocation.

Figure 3 is a view similar to Figure 2 with the parts in position at theextreme of reciprocation.

Figure 4 is a face view of the unit assembly with the casing coveromitted, and showing the drive and driven members, with the partslocated in the position of Figure 1.

Figures 5 and 6 are detail sectional view taken on lines 5-5 and 6-6,respectively, of Figure 4.

Figure '7 is a vertical longitudinal sectional view taken approximatelyon line 1! of Figure 4.

Figures 8, 9 and are detail sectional views taken on lines 88, 99, and[0-40, respectively of Figure 4.

The major feature of the present invention is the unit mechanism whichconnects the drive and driven member and which makes possible thparticular action of the invention assembly in service; an understandingof the fundamentals of this mechanism and its action is thereforedesirable before presenting the details, and for this purpose thediagrammatic showing of Figures 1, 2 and 3, will first be explained andanalyzed. The views present only those parts that are essential for theexplanation, the specific structural arrangement used in practice beingdisclosed in remaining views.

In Figures 1, 2 and 3, A represents the drive memberand B the drivenmember.

The drive i to ensure such stroke length with each cycle;

any suitable arrangement to provide this result may be employed, asimple illustration being that of a wind-Wheel operating mechanism whichconverts the rotary motion of the windwheel into the reciprocatingmotion of the drive member A, the stroke length being determined by thediameter of the circular path of the crank-pin or its equivalent,present in the translating mechanism. In the latter mechanism it isapparent that the crank-pin will pass upper and lower dead-centerpoints, these providing the limits of the stroke length of thedrivemember A.

As pointed out above, such rotary motion of the crank-pin serves to varythe speed of reciprocation of the member, the latter being greatest whenthe crank-pin is in the zone of the horizontal diameter ofreciprocation, the speed decreasing as the pin advances toward and intothe zone of the vertical diameter, although the speed of crank-pinadvance in its path remains constant; the variations set up in this wayhave the effect of gradually bringing the reciprocating stroke to itsend, since the decreasing speed decreases the value of the inertia ofmotion until such value becomes practically nil at the point Where thecrank-pin passes the dead-center point. As the pin advances afterpassing this point, it begins the stroke of reciprocation in theopposite direction, the length of movement per unit of time increasingas the pin advances.

Hence, the problems involved in such translation of motion from therotary to the reciprocating motion reach mainly to the end zones ofreciprocation, since it is in these zones that the inertia of motionmust come to its end to produce a momentary inertia of rest and then tobe followed by the starting of the succeeding inertia of motion activityin the opposite direction.

The speed of the crank-pin can have a definite efiect on the actionwithin such end zones, due to the fact that such speed controls the rateof inertia of motion decrease. Where the speed is high the momentum ofthe reciprocating member becomes of greater value and tends to opposethe decrease in value of the inertia of motion. Hence, unless provisionis made therefor, the assembly is generally limited as to the speed ofrotation, since the combination of forces in action within suchend-zones of reciprocation can set up damaging elTects such ashammer-blow, straining, etc. In some cases, cushioning devices, such assprings, etc., are employed, to absorb the shocks set up within suchzones, but these do not eliminate the difficulty, simply serving toreduce the effect of the shocks on the mechanism itself. Generally,therefore, in ordinary assemblages, such'as windwheel structures and thelike, the assemblies are arranged to provide a fixed maximum speed ofrotation, with the value placed sufilciently low as to reduce the shockcharacteristic to a minimum. Obviously, with such fixed maximum values,operation of the wind-wheel at lower speeds reduces the pumping value ofthe ap paratus, and therefore the efficiency.

Various ways of meeting the conditions have been employed, a favoriteone being that of providing a connecting mechanism between the drive anddriven members designed to increase the length of the stroke of thedriven member over that indicated by the diameter of the circular path,but the speed of rotation remains low in order to avoid the conditionsof shock; while such structures tend to increase the volume which can bepumped per stroke, the increase in stroke length also increases thedanger of shocks; such structures generally employ shock-absorbers andthe like.

In the present invention, the problem is met by deliberately increasingthe speed of rotationthe fixed maximum-and thereby increase the averagespeed of reciprocation, assuming that the power source S is of the typeindicated, the source being operatively connected to the drive member A,as by a link L, and setting up the characteristics of converting rotarymotion into reciprocating motion. With a lengthy pump rod as the memberA such speed increase would not be possible, since the weight of the rodwould provide an important factor in tending to maintain and increaseinertia of motion during the down stroke. With the present inventiondividing the pump rod into drive and driven members, it is possible toprovide a drive member A of relatively short length, so that the weightof the member is a comparatively small factor with respect to the valueof the inertia of motion of the drive member itself. Hence, it ispossible to increase the speed of rotation of the power source withoutsetting up damaging conditions within the end-zone of reciprocation ofthe drive member and especially the zone at the lower end ofreciprocation, since this zone is at the end of the down stroke duringwhich weight tends to augment the value of the inertia of motion.

To compensate and to reduce the conditions of shock brought about by theincreased speed, the present invention provides a mechanism which isnormally active as a direct connection between the drive and drivenmembersthus applying the same length and time of stroke action to bothmembersbut which, in the end zones of reciprocation of the members,serves to reduce the distance traveled by the driven member within suchzone to a value less than that traveled by the drive member within suchzone; since the time is the same for both members, the decrease indistance by the driven member renders the retarding action moreeffective, reduces the effect of momentum, and enables the inertia ofmotion to come to rest with minimum shock effect, even though the speedof rotation has been increased.

This result is obtained by interposing between the drive and drivenmembers A and B an interposed system of controlled leverage such asindicated diagrammatically in Figures 1, 2 and 3. This leverage islocated laterally and on opposite sides of the two members, the leveragesystem on one side being a duplicate of that at the opposite side butwith changed direction to provide a symmetrical action and to ensureuniformity in motion. Hence, a detailed description of the mechanism onone side will be sufficient.

The numeral I designates a pin on which the upper end of the drivenmember B is mounted, this pin passing through an elongated slot a formedwithin the drive member A, this arrangement permitting relative movementbetween the two members in the direction of reciprocation. Pin I9 isalso carried by the inner end of a leg II of a generally T-shaped leverI I the outer end of which carries the angular leg I I b of the lever,leg I I extending at approximate right angles to leg II the two legsbeing joined midway in the length of leg II Leg II is provided with apair of rollers I2 and I2 in the end zones of the leg.

Rollers I2 and I 2 are adapted to cooperate with a control face I3located laterally of the path of reciprocation of the members A and B,and has its central zone I 3 parallel with such path of reciprocation.The opposite end zones I3 and IS of the control face, however, arecurved inward toward the path of reciprocation for a desireddistancelongitudinally and laterally of the paththese zones I3 and I3"'also including an outer curved face I 3 and I 3 parallel with the faceof zones I 3' and I3, respectively. Control face I3 thus provides atrack over which the pair of rollers I2 and l2 can travel, such travelover the central zone I3 being parallel with the path of reciprocation,at which time both rollers will contact the face and leg II a willextend at substantial right angles to the path of reciprocation.

The leg II is operatively connected with drive member A by a link [4,the point of connection of the latter with the leg beinginward of themid-length of the leg. Since pin it is also carried by the inner end ofthe leg, and forms the support for the driven member B, the weight ofthe latter (assuming the path of reciprocation to be vertical) will beconstantly applied on to the shorter arm of the leg, thus constitutingthe leg I a to be a lever of the first order, with the link I l servingas the fulcrum. Hence, if the leverage is moved upward by the upwardmovement of the drive member, until roller I2 passes from the section I3of the control face on to the curved section I3 it will be apparent thatthe possible inward movement of the roller will permit the weight of thedriven member to rock leg I I on its fulcrum to the extent permitted bythe relief set up by the curved fac I3 it will be understood, of course,that as long as the weight of the driven member remains active as afactor on leg II the rocking of the leg will also move the leg i I withthe longer arm of the lever, thus moving the roller I2 inward whenrelief is present; in other words, the arrangement is such that theweight of the driven member will retain roller I2 in contact with thecontrol face in all positions of the travel of the drive member,excepting when the conditions, presently referred to, provide a superiorvalue to the leverage and thus temporarily overcome the weight of thedriven member as a factor.

Because of these conditions, the advance of the structure upwardly intothe end zone of reciprocation will, due to the curvature of face Itpermit leg II a to rock progressively and at rates dependent upon thecurvature of the face I3 Two positions are shown respectively in Figures2 and 3, the former indicating an intermediate position, with Figure 3being assumed to present the position of the parts at the instant whenthe power source is passing its upper dead-center position. Obviously,as leg I I a rocks, its angularity to the horizontal is changed, acomparison of Figures 2 and 3 with that of Figure 1, indicating thechange in leverage angularity set up by the movement of roller 62 fromsection I3 to section I 3* of the control face. As will be seen.

the rocking action of leg I l also has the effect of shifting roller l2from contact with the control face during this movement; this is due tothe fact that the lever ll rocks on the fulcrum link l4, so that theouter portion of the leverage rocks as a unit. This swinging of rollerl2 from contact does not affect the operation since the weight of thedriven member is being supported .by the shorter arm of leg H with thelatter supported by the drive member through link l4-rol1er I2 thuslimits the possible downward movement of pin under the weight of thedriven member, due to the contact of roller I? with the face [3 It".

However, the curved face l3 has an effect on .the angularity of leg Hsince the inward movement of the roller 12 permits the weight of thedriving member to seemingly lower the short .arm of the leg andtherefore of pin It; the lowering, however, is only relative, since(assuming the movement to be in the direction of upward travel) the linkfulcrum I4 is moving upward and carrying with it the lever ll, Hence,the actual result is that the advance of roller it over face l3 in theupward direction as lever H is being raised, also raises the drivenmember B but with the latter being raised a distance less than that ofthe drive member per unit of time, thus providing a differential in therate of upward advance as between the drive and driven members, the rateof the driven member being less than that of the drive member, with thevalue of the differential increasing as the point of contact of roller12 with face [3 moves inward relative to the plane of face lt thedifferential reaching its maximum at the instant when the drive memberreaches its upper dead-center position.

The effect of this action is to superpose upon the normal end-zoneconditions of the drive member, a driven member control in which thetiming is unchanged, but in which the distance "traversed per unit oftime is being curtailed as compared with the drive member, so that themomentum damping effect on the drive member set up by the dead-centerzone of the rotating power source, is being materially increased withrespect to the driven member, the latter moving upward under the controlof the leverage unit but by the power and speed of the drive member,with the length and rate of movement of the driven member less than thatof the drive member. It is apparent, therefore, that the speed of thedrive member can be increased materially without raising the approachrate of the driven member above that which would be considered safe instructures not employing the unit. In other words, the damping effectthat is present 'in the drive member is being augmented by the controlaction of the unit on the driven member, the unit taking over thecontrol of the endzone of reciprocation of the driven member the instantroller l2 begins to traverse the control face ltb, and providing itsindividual damping action on the driven member to supplement that whichis present in the drive member, the damping action of the drive memberserving to control the development of the augmenting damping action onthe driven member.

With both members in the upper dead-center positionFigure 3the upwardinertia of motion ends, with the succeeding momentary inertia of restfollowed by the beginning of the succeeding inertia of motion in theopposite di- ..rection, this taking .place when the crank-pin passes theupper dead-center point and advances angularly in its path of movement.This movement begins the downward movement of the drive member A, therate of advance being opposite to that provided during the upwardmovement. The downward movement of the drive member lowers link [4, thuslowering the fulcrum of leg Il and since the weight of the driven membertends to produce a movement of the latter in the same direction, theleverage carrier and the drive member begin the downward travel from theposition of Figure 3. However, the movement of the driven member isaffected, as during the upward travel. While the link I l is movingdownward-thus lowering the leg II and thus the leverage carrier (thelever H and rollers l2 and W), with the weight of the driven member anadded factor in tending to move the parts in this direction, the carriermovement can take place only by travel of roller [2 over the face ltb;the carrier movement is a bodily movement, since leg ll cannot rockbeyond the point determined by face 13'. Since face l3 is curved, andthe downward movement of the roller moves the latter outward, it isapparent that the relative effect of such movement would be to rock legH in the opposite direction, thus seeming to raise the driven member;actually, the effect is that of lowering the driven member at a ratedifferent from that of link I4; initially, the rate is that of themaximum differential referred to above, with the differential growingless as the roller traverses face I3 until the differential completelydisappears the instant roller l2 again reaches face l3 In other words,the development is the reverse of that presented during the upwardmovement within this zone, the parts passing from the position of Fig.3, through that of Fig. 2 to the po. sition of Fig. 1. During thistravel, the leverage angularity of leg II has been changing until itagain reaches the horizontal; during such change the rocking of leg Ihas rocked the carrier with the result that roller 12 is again broughtinto contact with face l3 thus having both rollers l2 and [2a activewith face l3 At this time (Fig, 1 the carrier is held against rockingsince both rollers are active to prevent yield; as a result, the carriermoves bodily with the link l4 and since pin It! is carried by thecarrier, the driven member will also move at the same speedthus settingup a one-to-one drive relation between the drive and driven members.

During the movement from the position of Fig. 3 to that of Fig. 1,therefore, there is a development of increasing speed by the drivenmember to gradually bring the driven member rate of advance up to thatof the drive member, this being brought about by the changes in leverageangularly of leg reaches the horizontal.

H until it again During this period the leverage differences provided bythe specific lopin H1 and the drive member is made possible bythepresence of slot a in the drive member, the pin occupying anintermediate position in Fig. 1, and moving to "the lower end of theslot in Fig. 3 during the upward travel, returning to the intermediateposition when the Fig. l position is resumed.

As the downward travel of the drive member and leverage carriercontinues, the carrier begins its approach to the lower end-zone ofreciprocation, with the lower roller l2a serving as the advance roller.While Fig. 1 indicates such end zone as the reverse of that shown at theupper end, the activities within the lower zone are slightly differentfrom those described, due to the fact that the weight of the drivenmember has remained active to retain roller l2 in contact with thecontrol face, and presumably remains active as a power source at alltimes. Hence, when the downward travel of the carrier causes roller H toreach the point of beginning of action in the zone of face 13' theweight of the driven member would tend to prevent roller 62 fromfollowing the curvature of face I3 However, guard face IS is located inposition to engage the outer face of roller H and hence, the continueddownward movement of the carrier brings roller I2 and the carrierwithinthe control face 3 face 13* being shown as curved inward to permit theinward travel of this roller under the action of face 13.

As Will be apparent, when roller [2 begins to traverse face I3, the facemoves the roller inward,- thus rocking the carrier. However, the rockingis now in the opposite direction, and therefore in opposition to theweight of the driven member, so that, in effect, face |3--in contrastwith face l3 acts as a positive forcing means superior to the weight ofthe driven member, with the result that the driven member is seeminglyforced upward as the roller advances; actually, the effect is to causethe driven member to be lowered at a slower rate than the link l4, thussetting up the development of the differential characteristics that arereferred to above in connection with the upper zone. Here, the leveragesuperiority of the roller end of the lever is of value in overcoming theweight factor of the driven member to increase efficiency.

In other words, the damping effect on the driven member results from twosources which are accumulative in effect. The damping action on thedrive member provided by the dead-center zone of the crank-pin travel iscommunicated directly to leg Il through the link I4, this controllingthe rate at which the leverage carrier can lower, and through which thecarrier advances roller I2 along face I3. In addition to this, however,the unit superimposes an additional damping action through the effect ofthe cooperation between roller 12 and face l3 during the roller advance,and which results in rocking leg H and thus the lever |lon its fulcrum,with the shorter end of the leg, with its pin l0, moving upward and thusin a direction opposite that being travelled by the carrier; however,the moving fulcrum passes downward faster than the shorter arm movesupward, so that the combined motion results in lowering the pin in butat a slower rate than the fulcrum. Hence, the downward travel of thedriven member is continued, but at a less rate than that of the drivemember with the differential increasing as the roller advances, untilfinally, the end of the down stroke of the drive member brings thefulcrum to the end of its stroke and ends the advance of the roller-withthe resultant end of the down stroke of the driven member.

During this development, the rigid and immovable face 13 forces therocking of the carrier, as indicated, with the result that the outer endof leg H and leg I l move in such manner that roller I2 leaves face l3and finally reaches a position relative to and distant from such facesimilar to that indicated in Fig. 3 in connection with roller 12*. Inthis position the angle of leg II is reversedcompared with thehorizontal from that shown in Fig. 3, and pin I2 is located at the upperend of slot l I; this latter results from the fact that the drive memberis moving at a greater speed than the pin, and hence the upper end ofslot a overtakes the pin. The position is not shown in the drawings, butcan be readily visualized by reversing the sheet so that the showing ofFig. 3 will then represent the lower end-zone of reciprocation insteadof the upper end-zone. In other words, the action in the two end-zonesof reciprocation during the approach to the dead-center positiontheinstant of inertia of rest conditionis similar, excepting that in theupper end-zone the effect is produced by the co-action of roller l2 withface I3 while in the lower end-zone the co-action is between roller [2and face I3, the co-action in both cases resulting in rocking leg I I ina direction opposing that of the movement of the drive member to therebydecrease the rate of advance of the driven member, and necessarilysetting up an accumulative damping effect additional to that provided bythe damping effect on the drive member, the two control faces W and I3,being active in opposition to the weight factor of the driven member,and with the leverage advantage of the longer arm of leg ll aiding inproducing the desired effect.

During downward travel of the driven member-assuming the latter to be apump rod with its control valve at the lower end-the valve remains open,so that the weight factor at this time is that of the driven memberalone. When,

however, the member reaches its lower limit of reciprocation, and thebeginning of the succeeding upward stroke is to take place, theconditions change through the fact that the valve closes, thus addingthe weight of the trapped content to that of the driven member; it isthis combined weight that must be brought into the status of inertia inmotion from the momentary status of inertia of rest present in thedeadcenter position. Unlike the conditions of the upper zone, thisweight factor is in opposition to the power at the beginning of thereturn stroke, and hence opposes the development of the return strokeinstead of aiding it as in the upper end zone.

It is in this condition that the unit presents a positive advantage,through the fact that although the rate of advance of the drive memberis initially slow, the rate of initial advance of the driven member ismuch slower; hence, the problems of overcoming the momentary inertia ofrest to begin the succeeding inertia of motion movement are slightlydifferent in the two members, since the ensuing rate of advance of thedriven member is less than that of the drive member at the instant ofchange. In action, the advance of the drive member A-as the power sourcepasses the lower dead-center positionis communicated to leg H throughlink [4, tending to raise the normal leg fulcrum; since the weight ofthe driven member is in opposition at this time, raising of the fulcrumwould tend to rock the leg due to the presence of the weight; but sinceleg H cannot rock in this direction without correspondingly movingroller 12* outwardly, the presence of guard face |3' prevents thedevelopment of this tendency. Consequently, there is momentarilydeveloped a power condition made up of the contact of roller l2 withface I3'acting as a temporary fulcrumand link I4 as the active powersource, with the power being exerted on leg Il the longer arm of the legbeing the fulcrum end, and with the shorter arm of the 1eg--with pin I-forming the weight to be moved. As a result, the power value becomesamplified on th driven member in the direction of raising the latter andat the same time the rate of advance of the drive member is materiallyhigher than that of the driven member, thus adding to the power effect,in that the length movement per unitof time is materially reduced asrespects the driven member. As a result, the combined forces active atthis instant are highly efficient in overcoming the momentary inertia ofrest of the driven member to thereby begin the succeeding inertia ofmotion in the stroke of the opposite direction.

After the inertia of rest has been overcome, the

driven member begins its upward travel, and

since inertia of motion is then present, the unit will then rapidlyreduce the differentiation in speed as between the drive and drivenmembers, through the fact that the curved face I3 permits rocking of thecarrier in the direction of the horizontal, until the point is reachedwhere roller Ii! again passes on to face l3 at which time the leg Ii ishorizontal, and the two members take up travel in unison or in theone-to-one relationship. overcoming inertia of rest, the differentia1 inspeed between the two members is at its maximum, with the leverageadvantage largely in favor of the power side and active; when inertia ofmotion develops, the differential in speed or rate is rapidly brought toa zero value to cause the two members to travel in unison until theupper end zone is again approached, thus beginning a repetition of thecycle.

It will be noted that in the above description the developments havebeen based on the face [3 and guard face l3 as the active faces. Wh'erethe pump is of the single-acting type and the conditions are such thatthe driven member is constantly active on the unit as a positive anddefinite weight factor, the two control faces referred tc--together withtheir counter-parts on the opposite side of the drive and drivenmemberswould be essential, and a unit having such arrangement (omittingthe guards [3 and control faces 13 is deemed to be within the presentinvention. However, it is possible that operating conditions may arisewhich could partially or wholly eliminate the weight of the drivenmember-es, for instance, a, tight-fitting valve formation, or imperfectvalve actionin which case the drive member must provide the power forthe movement and thereby set up the possibility of disturbing thecontrol relation between these faces and the rollers which co-operatetherewith, and to meet this condition, it is preferred that guards [3and faces 13 be included within the unit, these serving to preventmaterial departure from the regimen above pointed out, so far as the endzones are concerned, since these will prevent the lever H from beingrocked in directions to materially disturb the contact relationshipreferred to; when both rollers are contacting face w leg ll ishorizontal-e condition which remains undisturbed until one of the Inother words, at the instant of rollers is permitted to move inward as anendzone is entered. Where, as in double-acting pumps, there isresistance in both the upward and downward directions, the weight of thepump-rod is practically eliminated as a factor, and the structure wouldthen include all of the control faces referred to, the arrangement thenpractically making the control faces of the two end-zones as substantialduplicates.

The physical structure of the unit may be embodied in several forms oneof which is presented in the remaining figures of the drawings asillustrative of the fundamental features of the invention, it beingunderstood, of course, that changes and modifications designed to meetindividual conditions would require structural variations and these areconsidered as coming within the purview of the invention. For instance,it is obvious that the length of face l3 and the length, curvature,etc., of faces [3 and I3 may be varied to meet the conditions ofindividual installations; also, that the specific formation of the driveand driven members may be varied to meet conditions, the disclosurepresenting certain characteristics that should be present; since thesecan be provided in several forms it is apparent that the disclosure isto be considered as illustrative only.

In the embodiment shown, the unit structure is preferably mounted withina casing 20 of suitabl type and which may be arranged to contain alubricant-not disclosed-to place the moving parts in a bath oflubricant; the dimensions of the casing will depend upon theinstallation. If desired, the movable parts may be individuallylubricated instead, oil or grease cups being applied as may be foundnecessary.

The faces l3 l3 and I3 are carried by a member 2|, preferably extendingthe length of the casing and located at one side of the drive and drivenmembers; a similar member 2 l is located on the opposite side of thesemembers, the two members 2| and 2| presenting the control faces for thetwo leverage carriers which are also duplicated on opposit sides of thedrive and driven members, these carriers having their legs H projectinginwardly and connected with pin 10, the form shown presenting afabricated structure for simplicity of manufacture and efficiency inoperation. The members 2! and Zi have their inner faces cut away toprovide a space for the ready movement of parts longitudinally of thecasing, while the end zones of the members combine to form a trackbetween which the drive and driven members may move.

The drive member A is shown as of the laminated or skeleton type made upof two plate-like members 22, spaced apart by spacing means, etc., andwhich include guiding rolls 22 suit-ably positioned to ensure that themember will reciprocate in a constant path. The member is connected tothe power source in suitable manner, and extends downward beyond pinIt], plates 22 carrying the slot a within which pin It may move duringthe relative movement of drive and driven members as above explained.The plates 22 may, if desired, extend to the bottom of the casing toenable additional guide roller support, but, as pointed out above, theoverall length of the drive member A is short as compared with thelength of the driven member B.

The driven member B is preferably fabricated and shown as a pair ofplates 30 extending outside the plates 22, with the upper end zonemounted on pin [0 (Fig. 8) and may be guided within the unit by guiderollers; beyond the unit, the driven member may have any desired form.

The levers ll of the leverage carriers, are shown as spaced-apart plates23 for one carrier and 23 for the other carrier. These plates have thegeneral plan configuration shown in Fig. 4, but, as indicated in Fig. 8,the legs H of plates 23 are bent outwardly, this arrangement beingpreferred in order to enable the inner ends of legs 8 l to be assembledin simple manner within the zone about pin H]. For instance, Fig. 8indicates that the inner ends of legs Il of plates 23 lie between plates22 and 30, while the inner ends of the legs ll of plates 23 lie betweenspacers 24 and plates 22. Plates 23 and 23 carry the pairs of rollers l2and 12 one set for each carrier. Suitable spacing members 25 properlyposition the plates relative to each other. These pairs of plates 23 and23 and which produce th legs H and ll of Fig. leach carry a pin or bolt26 which provides the connection with leg I l of link [4; forconvenience, the disclosure presents these links as plates which arearranged as a single plate 21 mounted on pin 26 between plates 23--withits opposite end extending between members 22 and carried by a pin orbolt 28, and a pair of plates 2! connecting pin 28 with pin 26 of plates23 the pair of plates 2'! lying on the outer sides of members 22 andplates 23 as indicated in Fig. 8. Guard faces l3 and E3 are provided asshown.

This general arrangement permits the parts to be fabricated in plateform to produce the composite structures, thus providing strength andlightness to the assemblage. stood, of course, that the fabricated andskeletonized formation disclosed, while preferred, is illustrative,since the specific form and the arrangement can obviously be varied andthe parts be formed solid etc.

The unit will be supported in suitable manner to meet the individualoperating conditions, the drawings illustrating framing at the ends ofthe unit, arranged to properly locate the unit relative to the drive anddriven members, and to ensure a proper operation of the structure.

The arrangement thus disclosed is more or less illustrative, asheretofore explained, since it is apparent that variations can beutilized to meet different operating conditions, with such variationsutilizing the same general principles underlying the invention. Forinstance, in some cases it may be found desirable to locate links I4below instead of above pin l0, pin 28 being located below pin Illinstead of above the latter; in such case, the links would provide thesame fulcruming action as described, but the push and pull effect of thedrive member on the linkage carrier would be reversedthe upward movementof the drive member would serve to push the linkage instead of pullingitas illustrated in the drawings. Such variation could be of advantage incertain types of single acting cylinders, and is obviously a variationwhich falls within the purview of the present disclosure, and is to beconsidered as completely within the invention itself. In referring to a'push action, it will be understood, of course, that although thedirection of the movement of the drive member would be upward, thusdrawing pin 28 upward, the movement of pin 28 in the upward directionwould force the links l4which would then be at the opposite angles fromthose shown in the drawingsupward and thus push pins 26 upward, insteadof drawing them upward as illustrated.

It will be under- While I have herein shown and described the inventionas to its characteristics and operation, and have shown a specificembodiment of unit for carrying the same into effect, it is apparentthat the fundamentals presented are capable of application in variedways and that such applications will be subject to the particularenvironment in which it is made, so that it is obvious that changes andmodifications may be found desirable or essential in meeting thconditions of a particular installation, and I therefore desire to beunderstood as reserving the right to make any and all such changes andmodifications therein as may be found desirable or essential in meetingthe exigencies of service, insofar as the same may come within thespirit and scope of the invention as expressed in the accompanyingclaims, when broadly construed.

What is claimed as new is:

1. In motion-transmitting mechanism, a reciprocatory drive member, apower source operative to provide and control the timing and length ofreciprocation of such drive member, a reciprocatory driven member ingeneral alinement with the drive member, and a leverage unit operativelyconnecting the reciprocatory drive and driven members, said unit havinga direct drive connection with such drive member to thereby bodilyreciprocate the unit in coincidence with the drive member and havingdirect connection with the driven member to thereby drive the latter,said unit including means operative within the opposite end zones ofreciprocation by unit reciprocation for varying the drive relationbetween the members by varying the leverage angularity of lever elementsto thereby control the movement of the driven member within such zones,said driven member movements intermediate such zones being by the unitand in one-toone drive relation with such drive member with the overalllength of reciprocation of the driven member less than the similarlength of reciprocation of the drive member.

2. Mechanism as in claim 1 characterized in that the means includes acontrol face means operative to control the leverage angularity of thelever elements throughout the length of reciprocation of the unit.

3. Mechanism as in claim 1 characterized in that the means includes acontrol face means operative to control the leverage angularity of thelever elements throughout the length of reciprocation of the unit, saidcontrol face means having an intermediate portion extending inparallelism with the path of reciprocation of the members and having anend zone curved inwardly to provide end-zone leverage angularityvariations of the driven member.

4. Mechanism as in claim 1 characterized in that the means includes acontrol face means operative to control the leverage angularity of thelever elements throughout the length of reciprocation of the unit, saidcontrol face means having an intermediate portion extending inparallelism with the path of reciprocation of said members and havingits opposite end zones curved inwardly with like contours to therebyprovide and/ or permit end-zone leverage angularity variations ofsimilar characteristics in both endzones of reciprocation of the drivenmember.

5. Mechanism as in claim 1 characterized in that the means includes acontrol face means operative to control the leverage angularity of thelever elements throughout the length of reciprocation of the unit, saidcontrol face means ineluding an intermediate face portion extending inparallelism with the path of reciprocation of the members, an end zonecurved inwardly to provide end-zone leverage angularity variations ofthe driven member in one of the end zones of reciprocation of suchmember, and a guard face located at the opposite end of suchintermediate face portion, such guard face being curved inwardly andoperative to provide end-zone leverage angularity variations of thedriven member in the opposite end-zone of reciprocation of such member.

6. Mechanism as in claim 1 characterized in that the means includes acontrol face means operative to control the leverage angularity of thelever elements throughout the length of reciprocation of the unit, saidcontrol face including an intermediate face portion extending inparallelism with the path of reciprocation of the members, an inwardlycurved face portion at each end of such intermediate face portion and incontinuation therewith, and a guard face spaced opposite to andextending parallel with each curved face, to thereby provide and/orpermit end-zone leverage angularity variations of generally similarcharacteristic in both end-zones of reciprocation of the driven member.

7. Mechanism as in claim 1 characterized in that the means includes aleverage carrier and a control face formation in co-operativerelationship, said carrier being operatively connected with the drivemember to be driven thereby and also having a direct connection with thedriven member, said carrier and the control face formation beingco-operative to provide such one-toone drive relationship between thedrive and driven members within an intermediate range of travel of thedrive member and a differential rate of advance as between said memberswithin the end-zones of reciprocation of such drive member by leverageangularity variations within such end zones.

8. Mechanism as in claim 1 characterized in that the means includes aleverage carrier and a control face formation in co-operativerelationship, said carrier having a leverage assemblage and a pair ofrollers, the lever assemblage being operatively connected with the drivemember and having a direct connection with the driven member, theconnection with the drive member being at a point intermediate theconnection with the driven member and the rollers, said control faceformation being formed with an intermediate portion parallel with theline of reciprocation and inwardly-curved portions at the ends of suchintermediate portion, whereby the lever assembly will be retainedagainst rocking by contact of both rollers with the intermediate face toprovide the one-to-one drive relationship and will be rocked to vary theleverage angularity when one of the rollers contacts an inwardly-curvedface portion to provide the leverage angularity variations.

9. Mechanism as in claim 1 characterized in that the means includes aleverage carrier and a control face formation in co-operativerelationship, said carrier having a lever assemblage and a pair ofrollers, the lever assemblage being operatively connected with the drivemember and having a direct connection with the driven member, theconnection with the drive member being at a point intermediate theconnection with the driven member and the rollers, said control faceformation being formed with an intermediate portion parallel with theline of reciprocation and inwardly-curved portions at the ends of suchintermediate portion, whereby the lever assembly will be retainedagainst rocking by contact of both rollers with the intermediate face toprovide the one-to-one drive relationship and will be rocked to vary theleverage angularity when one of the rollers contacts an inwardly-curvedface portion to provide the leverage angularity variations, the secondof the rollers passing out of contact with the control face during suchleverage angularity variation.

10. Mechanism as in claim 1 characterized in that the means includes aleverage carrier and a control face formation in co-operativerelationship; said carrier having a lever assemblage and a pair ofrollers, the lever assemblage being operatively connected with the drivemember and having a direct connection with the driven member, saidcontrol face formation including an intermediate portion extendingparallel with the line of reciprocation, inwardly-curved portions at theend of such intermediate portion, and a guard face for and spaced fromeach inwardly-curved portion, the guard and curved faces defining atrack to receive a roller when moved into the zone of theinwardly-curved portion.

11. Mechanism as .in claim 1 characterized in that the means includes aleverage carrier and a control face formation in co-operativerelationship, said carrier having a lever assemblage and a pair ofrollers, the lever assemblage being operatively connected with the drivemember and having a direct connection with the driven member, saidleverage assembly including lever elements of approximately T-shapedconfiguration, with the rollers carried in the end-zones of thecross-leg of the configuration, with the connection with'the drivenmember carried in the free end zone of the other leg', and with theconnection with the drive member carried by and intermediate the ends ofthe latter leg to thereby permit rocking of the assembly about thelatter connection.

12. Mechanism as in claim 1 characterized in that the means includes aleverage carrier and a control face formation in co-operativerelationship, said carrier having a lever assemblage and a pair ofrollers, the lever assemblage being operatively connected with the drivemember and having a direct connection with the driven member, saidleverage assembly including lever elements of approximately T-shapedconfiguration, with the rollers carried in the end zones of thecross-leg of the configuration, with the connection with the drivenmember carried in the free end zone of the other leg, and with theconnection with the drive member carried by and intermediate the ends ofthe latter leg to thereby permit rocking of the assembly about thelatter connection, the point of connection with the drive member beinglocated to constitute the free end of the latter leg as the shorter armof the lever.

13. In motion-transmitting mechanism, a reciprocatory drive member, arotative power source operatively connected to the drive member toconvert the source rotary motion into reciprocatory motion of the drivemember with the "dead-center zones of travel of the source operative incontrolling the timing and length of reciprocation of the drive member,a reciprocatory driven member in general alinement with the drivemember, and a leverage unit operatively connected with the reciprocatorydrive member to be driven thereby and directly connected with thereciprocatory driven member to drive the latter, said unit beingoperative to maintain a one-to-one drive relation between thereciprocatory members during rotary travel of the power sourceintermediate the dead-center zones and operative by leverage angularityvariations to vary such drive relation between the members,

when the power source is within such deadcenter zones and with theoverall length of reciprocation of the driven member less than thesimilar length of reciprocation of the drive member to thereby controlthe end-zone damping of the drive member reciprocations by the powersource and to superimpose and augment endzone damping of the drivenmember reciprocations by unit leverage angularity variations made activeby and during dead-center zone activities of the power source.

14. Mechanism as in claim 13 characterized in that the unit includes aleverage assemblage having one of its legs operatively connected to bothdrive and driven members, said leg extending substantially normal to thepath of reciprocation of the members during the one-to-one driverelationship between the members and being angularly varied from suchnorma1 position during end-zone activities to thereby vary the driverelationship between the members.

l5. Mechanism as in claim 1 characterized in that the drive memberoverlies the opposite faces of the driven member within the unit zoneand is provided with guiding rolls co-operative with unit faces to limitdrive member movements to linear reciprocations, said member beingslotted to permit relative movement of the drive and driven members inthe direction of reciprocation during leverage angularity variations.

16. Mechanism as in claim 1 characterized in that the unit meansincludes a pair of co-operative leverage carriers and control faceformations positioned respectively on opposite sides of the drive anddriven members, with the drive member operatively connected with the twocarriers individually and with the driven member having a singleoperative connection with both carriers to thereby cause leverageangularity variations of both carriers to be common in direction andextent.

17. Mechanism as in claim 1 characterized in that the unit meansincludes a pair of co-operative leverage carriers and control faceformations positioned respectively on opposite sides of the drive anddriven members, with the drive member operatively connected with the twocarriers individually and with the driven member having a singleoperative connection with both carriers to thereby cause leverageangularity variations of both carriers to be common in direction andextent, each carrier having a skeletonized lever assemblage with a leverleg extending across the path of member reciprocation and with such legsoperatively connected with the driven member by a pin connection, eachcarrier having legs lying outside of opposite faces of the drivenmember.

18. Mechanism as in claim 1 characterized in that the unit meansincludes a pair of co-operative leverage carriers and control faceformations positioned respectively on opposite sides of the drive anddriven members, with the drive member operatively connected with the twocarriers individually and with the driven member having a singleoperative connection with both carriers to thereby cause leverageangularity variations of both carriers to be common in direction andextent, each carrier having a skeletonized lever assemblage with a leverleg extending across the path of member reciprocation and with such legsoperatively connected with the driven member by a pin connection, eachcarrier having legs lying outside of opposite faces of the drivenmember, the drive member being connected with one carrier by a singlelink and with the other carrier by a pair of links alined and spacedapart.

BRYAN BRAS SELL.

